Reciprocating internal combustion engine



v F. NEITEL 2,846,987

Aug. 12, 1958 RECIPROCATING INTERNAL COMBUSTION ENGINE Filed March 13, 1956 U I INVENTOR FEEDL'E/CK )YEITLL ar- .6 45.1.4 dimweg H'rnRNe ipumps.

United States Patent l RECIPRO'CATING INTERNAL COMBUSTION ENGINE FrederickNettel, Manhasset, N. Y.

Application March 13, 1956, Seri'al'No. 571,205 17 Claims. (Cl. 123-4142) This invention :relates to reciprocating internal combustion engines and is applicable to diesel, gasoline, gas and dual-fuel engines of the twoand four-cycle type having one or more cylinders, air or liquid cooled.

Known engines of these types use for feeding fuel into the cylinders either carburators or fuel injection Carburators are suitable only for low-boiling hydrocarbons and involve elaborate manifolding for multicylinder four-cycle engines and fuel losses during scavengting when applied to two-cycle gasoline engines. The known fuel injection pumps are complicated, require special drives and are therefore expensive to build and tomaintain.

The principal object of this invention is to :reduce or eliminate these disadvantages and to simplify the design and operation of the engines.

This is achieved by arranging a fuel chamber as part of the cylinder head in which a fuel pump barrel is disposed, with its open end in connection with the cylinder interior, said barrel engaging with a fuel pump plunger connected at one end to the piston crown. The fuel chamber is connected to the pump barrel interior by an adjustable conduit. The pump plunger has an axial bore and a nozzle connected to it at a point near the piston crown, for injecting fuel into the cylinder.

.For 'a consideration of other objects and of What I believe to be novel and my invention, attention is directed to the following description and the claims appended thereto in connection with the accompanying drawings.

In the drawings, which illustrate by way of non-limiting examples embodiments of my invention:

Fig. 1 shows a sectional view of an air cooled twocycle spark ignition engine.

Fig. 2 a section of the cylinder of the engine as per Fig. 1.

Fig. 3 indicates a .section through part of the cylinder head with a device for regulating the fuel level in the fuel chamber.

vFig. 4 reveals an arrangement for circulating .fuel between the cylinder head and the fuel tank.

Fig. 5 shows a section through the cylinder of an engine according to .my invention in which the fuel chamber surrounds substantially the whole outer :surface of the cylinder, with the fuel being used as cooling medium.

Fig. 6 depicts a cylinder head with a cooled fuel chamber *of small volume.

Reverting now in more detail to .Fig. .1 in which 1 denotes the engine cylinder in the head of which is incorporated a cylindrical fuel chamber 2, 3 is the piston with air deflector rib 4, while 5 is the connecting rod and 6 the crankshaft. The cylinder is provided near the inner dead center with ports 7 for air intake and ports 8for gas exhaust :as is conventionalfor two-cycle engines.

Within a cylindrical recess 9 in the fuel chamber 2, aspark plug 10 is positioned as shown. The'fuel chamber contains further a cylindrical insert 11 with its .axis

' parallel to the axis of the engine cylinder, said'insert be- 2,846,987 Patented Aug. 12, 1958 ice ing in communication at its lower end with the engine cylinder and threaded at its upper end. Port openings 12 connect the fuel chamber with the interior of the insert. The injection pump barrel 13 is screwed into said insert. The upper end of the barrel 13 is closed by a nut 14 with counter-nut '15. Central to the nut 14 a nonreturn spring loaded ball valve 16 may be arranged which connects the pump barrel with the atmosphere when the pressure in the barrel drops below a predetermined pressure. The pump barrel 13 is disposed to be rotated within the insert 11 by means of a lever 17 connected to the nut 14. The pump barrel is further equipped with port holes 18 adjustably meshing with the ports 12, thus permitting adjustable quantities of fuel to flow from the fuel chamber 2 into the interior of the barrel 13. 19 denotes the fuel pump plunger arranged to mesh with the barrel '13. This plunger has a central bore 20 at the lower end of which a spring loaded non-return ball valve 21 may be arranged, as shown which closes when the fuel pressure within the bore drops below a predetermined value. The plunger '19 is screwed into the crown of the piston 3 at its lower end. Below the valve 21 a small nozzle bore '22 is provided connecting the plunger bore with the cylinder interior. This nozzle 22 is located so that the fuel spray issuing from it does not impinge on the deflector rib 4 or the cylinder walls. The fuel enters the fuel chamber 2 through the pipe 23 from a fuel tank (not shown). The pipe 24 with cock '25 may be used to discharge sediments from the bottom of the fuel chamber which may accumulate there.

Fig. 2 shows a section through the cylinder along the line AA indicated in Fig. 1. From it the location of the plunger in the engine cylinder can be seen. Also the nozzle location is shown by dotted lines with its axis in the general direction toward the spark plug 10 whose position relative to the nozzle is indicated by a small circle. The deflector rib 4-has arc shape surrounding the plunger 19 at its lower end.

Fig. 1 indicates the engine piston 3 in its lowest position '(inner dead center) with both the air intake ports 7 and the gas exhaust ports 8 uncovered by the piston 3. The ports '7 are normally connected with a source of air at a pressure more or less above atmospheric pressure (not shown). In this position the 'plunger 20 protrudes into the barrel 13 to a point below the ports 18. When the piston is in its highest position (outer dead center) the plunger '20 will have risen to fill the barrel 13 substantially completely. The spark plug '10 is energized in the conventional manner by a magneto or battery permitting proper adjustable timing of the ignition.

The starting and operation of the engine is as follows:

The fuel chamber 2 is assumed to be filled with liquid fuel.v The barrel 13 is rotated into such position relative to the insert ports '12 that no fuel can reach the interior of barrel 13 through the ports 18. Next the ports '7 are connected to the air source, so that air begins to flow through the cylinder and out through the .ports 8. Now the engine is cranked by any conventional means and the barrel 13 rotated until a small fuel flow is established from the chamber 2 'via ports "12 and 18 .into the barrel 13. This fuel is lifted by the rising plunger 19 and forced into the central bore 20 until the whole central bore is filled with fuel. If, by further cranking, more fuel is pumped into the bore 20 a pressure will build up in it which opens the valve 22 and permits the fuel to flow through the nozzle 22 in the form of a spray into the cylinder where it mixes with the compressed air charge near the end of the upward stroke of the piston. This air-fuel mixture is now ignited by the spark plug and the gases of combustion drive the piston downwards While expanding and producing useful work until the piston uncovers the ports 8 which permit the spent gases to escape. Shortly afterwards the ports 7 are also uncovered, admitting a new air charge to enter and to drive the spent gases out, i. e. to scavenge the cylinder. On the following compression stroke ports 7 and 8 are closed in sequence and the cycle is repeated.

With increasing load more fuel is needed. This is provided by rotating the barrel 13 in such manner as to increase the fuel fiow into the barrel 13 per working stroke via the ports 12 and 18. If the load is to be reduced the reverse motion of the barrel 13 will admit less fuel per working stroke. It is Within the scope of this invention to combine this method of fuel regulation with regulation of the air charge entering the cylinder by throttle means in the air conduit to the cylinder or other conventional means.

The barrel 13 is screwed into the insert i2 in such a way that when the ports 18 are being closed the barrel rises. This will cause a dead space for the fuel to develop at the barrel top further reducing the fuel quantity pumped into the cylinder and facilitating fuel regulation especially idling of the engine. Instead of the thread on the barrel 13 a shoulder can be provided, held in the insert, permitting rotation without axial movement. The fuel chamber 2 which is shown as part of the cylinder head will heat up quickly after the engine has started. This is desirable when higher boiling fuels are to be utilized in the engine because hot fuel has a lower viscosity and impurities in the fuel can settle at the bottom of the chamber and discharge through the pipe 24.

If the fuel is heated above its boiling point it is necessary to maintain a positive pressure in the fuel chamber to prevent vapor lock. This can be done either by a fuel tank 40 located above the fuel chamber and/ or by a fuel pump 41, as per Fig. 4. In order to prevent a too high fuel temperature a closed flow circuit of fuel through the pipe 46 can be maintained by pump 41 between the fuel chamber 2, the radiator-cooler 45 and the fuel tank 40 by means of the thermostat device 42 with bellows 43 controlling the exit temperature of the fuel from the fuel chamber 2 by operating the valve 44 as shown in Fig. 4.

The fuel in the pipes and tank will be heated up too, which is desirable when viscous fuels have to be handled.

For certain fuels it may be desirable to keep only a small the fuel chamber 2 very small, for example in com- 7 pression-ignition engines using special fuels, as shown in Fig. 6, with the injection pump barrel 13 arranged centrally to the cylinder and the chamber exterior provided with radiator ribs. Other cooling media such as water for example, may be used.

The proposed arrangement of the pump plunger within the engine cylinder is made practicable by the fact that during most of the period of fuel combustion it is hidden within the barrel 13, which is kept comparatively cool by the fuel.

Furthermore, in two-cycle engines the plunger can be disposed in such a position as to be very effectively cooled by the air charge entering through the ports 7. When the engine has to start from cold, it may be desirable to preheat the fuel for which, as shown in Fig. 1 an electric heating cartridge 26 or another conventional heat source can be applied.

When starting on heavy fuels is necessary, this may be facilitated by introducing low boiling fuel such as gasoline, ether etc. into the fuel chamber, as shown in Fig. 5, where 50 is the container for the starting fuel and 51 a valved pipe connecting it to the fuel. chamber. Such priming can also be done conveniently by introducing low boiling fuel directly into the pump barrel 13 through the valve 16. As indicated in Fig. the fuel chamber may be.

extended to surround the cylinder walls so that the fuel is used also as cooling medium for the engine. Some of the hot fuel may be branched off from the fuel chamber via the valved pipe 52 for use in a consumer external to the engine, for example in a heat exchanger, burner etc. Using hot fuel has many advantages, in particular also for engines Working on the compression-ignition cycle, because it is possible to reduce the compression ratio since no or little heat has to be provided by the compressed air to ignite the fuel. Besides, as experiments have shown, a smoother combustion is achieved.

While my engine is particularly suited for two-cycle operation, it is possible to operate on four-cycle by making the fuel pump operative only during every second revolution. This can be done by opening the valve 16 during every second revolution thus interrupting the pumping of fuel periodically. Such valve control can be effected as done in conventional engines from a camshaft driven at half of the crank speed or other known means (not shown).

It is immaterial for the purposes of this invention what kind of fuel is used, liquid or gaseous or both simultaneously, what type of load and/or speed control is employed, what number and arrangement of cylinder or cylinders is used, whether the engine is supercharged or not and what type of power consumer it is connected to. It will be understood that my invention is not intended to be restricted to the specific examples of structure or operation given hereinbefore, and is intended to cover all changes and modifications of the examples of the invention herein chosen for purposes of disclosure which do not constitute departures from the spirit and scope of the invention.

I claim:

1. Reciprocating internal combustion engine for liquid or gaseous fuels having a-cylinder, cylinder head, piston, piston rod and crankshaft, comprising a fuel injection pump plunger mechanically connected at one end to the piston crown, a fuel chamber connected to said cylinder head, a pump barrel arranged in said fuel chamber with its open end in connection with the cylinder interior disposed to engage with said pump plunger, valved conduit means for connecting said fuel chamber with the said pump barrel, said pump plunger having an axial bore and nozzle means connecting said bore with the cylinder interior at a point near the piston crown for injecting fuel into said cylinder.

2. Reciprocating internal combustion engine as set forth in claim 1, having means for regulating the flow of fuel through said conduit means from said fuel chamber to said pump barrel.

3. Reciprocating internal combustion engine as set forth in claim 1, having a spring-loaded stop valve interposed between the axial bore of the pump plunger and the nozzle means, for preventing fuel discharge into the cylinder when the said plunger is not displacing fuel from the barrel.

4. Reciprocating internal combustion engine as set forth in claim 1, the pump barrel having a spring-loaded valve at its normally closed end, for connecting the barrel interior with the ambient atmosphere.

5. Reciprocating internal combustion engine as set forth in claim 1 disposed to operate with a compression ratio in excess of 8:1 with ignition of the fuel by preheating of the fuel and by the compression heat of the working air charge.

6. Reciprocating internal combustion engine as set forth in claim 1, having electric means for igniting the mixture of the compressed working air and the fuel injected through said nozzle means.

7. Reciprocating internal combustion engine as set forth in claim 1, having inlet ports for the working air and outlet ports for the combustion products both near the inner dead center with the engine being disposed to operate as two-cycle engine.

8. Reciprocating internal combustion engine as set forth in claim 1, having a cylinder head forming a closed fuel chamber. I

9. Reciprocating internal combustion engine as set forth in claim 1, having a closed fuel chamber, a fuel tank, and valved conduit means connecting said fuel chamber with said fuel tank.

10. Reciprocating internal combustion engine as set forth in claim 1, having a closed fuel tank, valved conduit means for connecting said fuel tank with said fuel chamber and means for putting said fuel chamber under a controllable pressure above the atmospheric pressure.

11. Reciprocating internal combustion engine as set forth in claim 1, having means disposed in said fuel chamber for controlling the fuel level in said chamber.

12. Reciprocating internal combustion engine as set forth in claim 1, having a closed fuel tank, conduit means for connecting said fuel chamber with said tank, valved conduit means for discharging fuel from said fuel chamber, thermostatic control means in operative connection with said valve means for discharging fuel, for maintaining a predetermined fuel temperature in said fuel chamber irrespective of the operating condition of the engine.

13. Reciprocating internal combustion engine as set forth in Claim 1, having a discharge valve means disposed near the bottom of said fuel chamber, for discharging impurities contained in the fuel which settle at the bottom of said fuel chamber.

14. Reciprocating internal combustion engine as set forth in claim 1, having a fuel chamber extending downward over the circumference of said cylinder for using the fuel as cooling medium for said cylinder.

15. Reciprocating internal combustion engine as set forth in claim 1, having a plurality of cylinders.

16. Reciprocating internal combustion engine as set forth in claim 1, having a fuel chamber equipped with cooling means to limit the fuel temperature in said chamber.

17. Reciprocating internal combustion engine for liquid or gaseous fuels having a cylinder, cylinder head, piston, piston rod and crankshaft, comprising a fuel injection pump plunger mechanically connected at one end to the piston crown, a fuel chamber, a pump barrel with its open end in connection with the cylinder interior disposed to engage with said pump plunger, conduit means for connecting said fuel chamber with the said pump barrel, said pump plunger having an axial bore and nozzle means connecting said bore with the cylinder interior at a point near the piston crown for injecting fuel into said cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 1,386,832 Bailly Aug. 9, 1921 FOREIGN PATENTS 360,057 Germany Sept. 29, 1929 

